A mobile node may access packet data services through a wireless service provider. When accessing packet data services, the mobile node may identify itself by a network access identifier (NAI) that has been assigned to it by the wireless service provider. For example, a mobile node may identify itself by NAI when registering for Mobile IP services. The Mobile IP services may involve IPv4 addresses, for example, as described in C. Perkins, “IP Mobility Support for IPv4,” Request for Comments 3344, August 2002, which is incorporated herein by reference. Alternatively, the Mobile IP services may involve IPv6 addresses, for example, as described in D. Johnson et al., “Mobility Support in IPv6,” Request for Comments 3775, June 2004, which is incorporated herein by reference.
The NAI may conform to the standards set forth in B. Aboba et al., “The Network Access Identifier,” Request for Comments 4282, December 2005, which is incorporated herein by reference. Thus, the NAI may be in the form of “username@realm.” The “realm” typically corresponds to a domain name associated with the wireless service provider. The “username” is typically assigned by the wireless service provider, for example, based at least in part on the subscriber's name. Thus, a subscriber named John Doe might be assigned a username of “jdoe01” by the wireless service provider.